In Vedic Sanskrit about 150 forms in -si, formed from 23 roots, are used as imperatives of the 2nd singular. Among the most frequent in the Rigveda are yakṣi ‘sacrifice’ (34 times), vakṣi ‘carry, bring’ (25 times), parṣi ‘bring across’ (16 times), neṣi ‘lead’ (10 times), darṣi ‘pierce’ (10 times), satṣi (10 times), rāsi ‘bestow’ (8 times). Until quite recently the position of these forms within the Vedic verbal system has usually been left undecided. In 1955 Burrow merely noted that their ‘termination is identical with that of the 2 sg. indic, pres., but these indicatives are quite clearly distinguished because the presents are differently formed’. Three years earlier, Renou expressed the view that the type in question was ‘une formation autonome, où une ancienne désinence -s a pu être prolongée par un i déictique’. The decisive advance, alluded to above, is due to the recent work of Johanna Narten, but especially to George Cardona's excellent paper published only a year ago. Whereas Narten still insisted that the formation was ‘bildungsmässig ausserhalb des Tempussystems stehend’ (39), although she admitted that in several cases the imperative in -si ‘im vedischen Sprachgefühl wohl zum s- Aorist gerechnet [wurde]‘ (45), Cardona cogently showed that the -si imperative was not only part of the s-aorist system but was most closely linked with the s-aorist subjunctive.